1. Field of the Invention
This invention is related to my earlier application with an application number of Ser. No. 09/360/835, entitled xe2x80x9cEfficient Paste Dispenserxe2x80x9d, abandoned due to a lack of detailed specifications which, with its novel features could have distinguished itself from prior art. The invention deals with a collapsible tube paste dispenser for dispensing paste materials such as toothpaste, medicinal creams and ointments.
2. Prior Art
Heretofore, it is not easy to squeeze out the last bit of paste from a conventional collapsible tube dispenser. The tube will collapse into irregular shapes with pockets of paste inside that even people with strong fingers will find difficult to tackle. There are a few attempts in the past to solve this problem, exemplified by Stazdins"" xe2x80x9cCollapsible Tube Containersxe2x80x9d, with U.S. Pat. No. 3,648,895, wherein the tube wall is comprised of even number of longitudinal plates connected by thin areas that form hinge lines in between these longitudinal plates. When pressed onto each other, these plates are supposed to aid the evacuation of the paste. The outlet is disposed along the longitudinal axis of the tube. In the shoulder area near the connection between the outlet and the tube, one side of the tube is thinner than the other side, so that the thinner side will collapse onto the thicker side of the tube, supposedly leaving no wrinkles. Stazdins does not teach how the thin part would collapse onto the thick part in the shoulder area where the tube gradually narrows down to meet the axially mounted cylindrical outlet. According to the two-dimensional drawings provided, Stazdins implies that the thick part will remain flat so that the thin part can be pressed onto it easily. There is no where in the drawings that suggests a concave plate where the thin part can collapse into. In reality, in a three-dimensional situation, the shoulder area near the connection to the axially mounted outlet, is likely to be forced into forming a deep and narrow depression where the thin part is impossible to collapse into. This problem can not be avoided as long as the outlet is axially mounted. Furthermore, the segmented tube wall with thick areas hinged together by thin hinge lines will do very little in helping the total. evacuation of the contents. But the cost of making such will be greatly increased. Conventional tube walls with uniform thickness and flexibility will be just as effective.
Other attempts to solve the problem such as Chen""s xe2x80x9cSelf-closing Liquid Dispensing Packagexe2x80x9d with U.S. Pat. No. 5,529,224 and O""Conner""s xe2x80x9cDisposable Shaker Packetxe2x80x9d with U.S. Pat. No. 2,956,710 are for holding and dispensing very small quantities of contents. They do not, and neither do they need to have an end plate to support a rigid outlet structure, as does the current invention. They are not symmetrical in a manner so that one side will collapse and fit perfectly into the other side, so that the contents can be completely evacuated. There will be inevitably pockets, creases, and wrinkles formed in between the two sides.
It is an object of this invention to provide a collapsible tube paste dispenser that can easily and smoothly empty all its contents.
This is a collapsible tube dispenser for paste. It can totally-and smoothly evacuate its contents by collapsing one part of the tube into another part of the tube and the two parts will fit perfectly together without pockets, creases, and wrinkles, because the two parts are symmetrical. There is a broad, smooth, concave, rigid end plate mounted at one end of the tube and laterally on one side of the longitudinal axis of the tube. An outlet structure is not mounted axially along the longitudinal axis of the tube, as that in a conventional paste dispenser, but mounted laterally on one side of the longitudinal axis, on the laterally mounted end plate. When the collapsible and symmetrical counter part of the end plate collapses into the end plate, the two parts will fit perfectly and smoothly, forcing out the last bit of paste through the laterally mounted outlet.